微胶囊固体酸酸化压裂技术应用及展望

常规酸化压裂工作液体系存在酸岩反应过快、有效作用距离短等问题,微胶囊固体酸是解决该问题的有效手段之一,其常用于对非常规油气藏进行深度酸化压裂。此次研究阐述了微胶囊固体酸的作用机理、结构和性能特点,总结了微胶囊固体酸酸化压裂技术的研究进展,指明了微胶囊固体酸酸化压裂技术未来的主要研究方向。该研究可为超高温碳酸盐岩油藏的增产改造提供技术支持,并为微胶囊固体酸酸化压裂技术的研究与应用推广提供理论指导。

聚苏氨酸修饰铅芯电极同时测定尿酸、黄嘌呤和次黄嘌呤

制备一种简单、低成本的聚合膜修饰电极,用于黄嘌呤(XA)、次黄嘌呤(HX)和尿酸(UA)的同时测定。单线扫描伏安法。在聚苏氨酸修饰铅芯电极上,XA,HX和UA的电化学氧化信号均得到显著增强,氧化过电位不同程度降低。同时在UA、XA和HX共存时,PT/PGE可以选择性、无干扰的测定每一种嘌呤,且其氧化峰电流与XA、HX和UA的浓度在一定范围内均呈良好线性关系。该电极对UA、XA和HX的电化学检测具有优异的电催化特性,可用于实际样品中XA、HX和UA的同时测定。

玉米芯稀酸水解液灭菌方式对Clostridium acetobutylicum XY16发酵性能的影响

玉米芯稀酸水解液(CDAH)中抑制物含量影响其制备生物丁醇的发酵性能。对玉米芯稀酸水解液的灭菌处理方式(如pH,灭菌温度等)与抑制物含量变化的关系进行研究。结果表明:pH、灭菌温度、水解糖液总糖浓度对蒸汽灭菌过程中抑制物的产生有显著影响,在优化的灭菌条件(总糖质量浓度70 g/L,pH 4.0,灭菌温度115℃,灭菌时间15 min)下,灭菌后的水解糖液中,糠醛11.2 mg/L,羟甲基糠醛(HMF)43.4 mg/L,单酚74.3 mg/L,多酚46.7 mg/L。产丙酮丁醇梭菌Clostridium acetobutylicum XY16能利用水解糖液,总糖质量浓度为40 g/L时,丙酮、丁醇和乙醇(ABE)质量浓度达到11.78 g/L,其中丁醇为7.36 g/L,和传统灭菌处理(121℃,15 min)及过滤除菌处理的水解糖液相比,丁醇、丙酮和乙醇(ABE)质量浓度分别提高了129%和228%,丁醇质量浓度分别提高了116%和259%。

HPLC法测定玉米芯酸水解液中糖组分的含量

建立高效液相色谱法测定玉米芯酸水解液中糖组分。采用AminexHPX-87H柱（300mm×7.8mm）,以0.01mol/L硫酸为流动相,流速为1.0mL/min,柱温：60℃,检测器为示差检测器;进样量20uL。结果表明：以峰面积定量,葡萄糖的线性范围为10~50ug（r=0.9999）;平均回收率99.6%、RSD=0.73%（n=9）。木糖的线性范围为20~100ug（r=0.9999）;平均回收率99.8%、RSD=0.45%（n=9）。、阿拉伯糖的线性范围为10~50ug（r=0.9997）;平均回收率100.2%、RSD=0.88%（n=9）。该方法简便、结果准确可靠,可用玉米芯酸水解液中糖组分的测定。

Altered Gene Expression in Articular Chondrocytes of Smad3^(ex8/ex8) Mice, Revealed by Gene Profiling Using Microarrays

It has been previously reported that small mother against decapentaplegic 3 （Smad3） gene knockout （Smad3^ex8/ex8） mice displays phenotypes similar to human osteoarthritis, as characterized by abnormal hypertrophic differentiation of articular chondrocytes. To further clarify the crucial target genes that mediate transformation growth factor-β （TGF-β）/Smad3 signals on articular chondrocytes differentiation and investigate the underlying molecular mechanism of osteoarthritis, microarrays were used to perform comparative transcriptional profiling in the articular cartilage between Smad3^ex8/ex8and wild-type mice on day five after birth. The gene profding results showed that the activity of bone morphogenetic protein （BMP） and TGF-β/cell division cycle 42 （Cdc42） signaling pathways were enhanced in Smad3^ex8/ex8 chondrocytes. Moreover, there was altered gene expression in growth hormone/insulin-like growth factor 1 （Igfl） axis and fibroblast growth factor （Fgf） signaling pathway. Notably, protein synthesis related genes and electron transport chain related genes were upregulated in Smad3^ex8/ex8 chondrocytes, implying that accelerated protein synthesis and enhanced cellular respiration might contribute to hypertrophic differentiation of articular chondrocytes and the pathogenesis of osteoarthritis.

Regulation of the cell cycle gene, BTG2, by miR-21 in human laryngeal carcinoma

MicroRNAs are short regulatory RNAs that negatively modulate gene expression at the post-transcriptional level, and are deeply involved in the pathogenesis of several types of cancers. To investigate whether specific miRNAs and their target genes participate in the molecular pathogenesis of laryngeal carcinoma, oligonucleotide microarrays were used to assess the differential expression profiles of microRNAs and mRNAs in laryngeal carcinoma tissues compared with normal tissues. The oncogeuic miRNA, microRNA-21 （miR-21）, was found to he npregulated in laryngeal carcinoma tissues. Knockdown of miR-21 by specific antisense oligonucleotides inhibited the proliferation potential of HEp-2 cells, whereas overexpression of miR-21 elevated growth activity of the cells, as detected by the colony formation assay. The cell number reduction caused by miR-21 inhibition was due to the loss of control of the G1-S phase transition, instead of a noticeable increase in apoptosis. Subsequently, a new target gene of miR- 21, BTG2, was found to be downregulated in laryngeal carcinoma tissues. BTG2 is known to act as a pan-cell cycle regulator and tumor suppressor. These findings indicate that aberrant expression of miR-21 may contribute to the malignant phenotype of laryngeal carcinoma by maintaining a low level of BTG2. The identification of the oneogenic miR-21 and its target gene, BTG2, in laryngeal carcinoma is potentially valuable for cancer diagnosis and therapy.

Detection of hepatitis B virus genotypes using oligonucleotide chip among hepatitis B virus carriers in Eastern China

AIM： TO determine the genotype distribution of hepatitis B virus （HBV） with a newly oligonucleotide chip assay among the HBV carriers in Eastern China. METHODS： An assay using oligonucleotide chip was developed for detection of HBV genotypes in serum samples from HBV DNA-positive patients in Eastern China. This method is based on the principle of reverse hybridization with Cy5-labeled amplicons hybridizing to type-specific oligonucleotide probes that are immobilized on slides. The results of 80 randomly chosen sera were confirmed by direct sequencing. RESULTS： HBV genotype B, C and mixed genotype were detected in 400 serum samples, accounting for 8.3% （n = 33）, 83.2% （n = 333）, and 8.5% （n = 34）, respectively. The evaluation of the oligonucleotide assay showed 100% concordance with the amplicon phylogenetic analysis except 9 mixed genotype infections undetected by sequencing. CONCLUSION： The study indicates that HBV genotype C and B prevail in the Eastern China. It is suggested that the oligonucleotide chip is a reliable and convenient tool for the detection of HBV genotyping.

Oligonucleotide chip, real-time PCR and sequencing for genotyping of hepatitis B virus

To compare the oligonucleotide chip, real-time PCR and sequencing for genotyping of hepatitis B virus in Chinese patients with chronic hepatitis B. METHODS： Mixture of samples with different genotypes and clinical serum samples from 126 chronic hepatitis B patients was tested for hepatitis B virus genotypes by oligonucleotide chip, real-time PCR and sequencing of PCR products, respectively. Clinical performances, time required and costs of the three assays were evaluated. RESULTS： Oligonucleotide chips and real-time PCR detected 1% and 0.1% genotypes, respectively, in mixed samples. Of the 126 clinical samples from patients with chronic hepatitis B, genotype B was detected in 41 （33%）, 41 （33%） and 45 （36%） samples, and genotype C in 76 （60%）, 76 （60%） and 81 （64%） samples, by oligonucleotide chip, real-time PCR and sequencing, respectively. Oligonucleotide chip and real-time PCR detected mixed genotypes B and C in 9 samples. Real- time PCR was the rapidest and cheapest among the three assays. CONCLUSION： Oligonucleotide chip and real-time PCR are able to detect mixed genotypes, while sequencing only detects the dominant genotype in clinical samples.

Meta-analysis gene lists about subtypes of leukemia based on gene expression data

To screen for molecular signatures that are commonly dysregulated in subtypes of a certain cancer, a novel meta-analysis is designed to perform rank score （RS） on lists of genes that are derived from different studies. RS is a promising way to detect signatures across platforms when integrating with one vs. all （OVA） or one vs. one （OVO） schemes of comparison. Among six published microarray expression datasets on acute leukemia, the biological signals hereafter provide stronger clustering support than systematic differences among microarray platforms. Moreover, the pediatric BCR_ABL specific genes can be used to correctly discriminate independent adult BCR ABL cases. The obtained results redound to discover, validate and treat the subtypes from microarray gene expression profiles of cancer, which have been plentifully researched, such as leukemia.

STAT3 Inhibition by Centipede Scolopendra Extract in Liver Cancer HepG2 Cells and Orthotopic Mouse Models of Hepatocellular Carcinoma

Objective To observe the effects of Centipede Scolopendra extraction(CSE)on human liver cancer HepG2 cells and the nude mouse tumor model of liver orthotopic transplantation,and to explore the anti-liver cancer mechanism of the extract.Methods HepG2 cells were respectively treated with CSE250(250μg/mL),CSE500(500μg/mL)and 5-FU,and control group was established.An enzymatic hydrolysis and acetone precipitation method was used to separate and purify CSE,which was then used to treat HepG2 cells.The CCK8 assay was used to detect the inhibition of cell proliferation and the half maximal inhibitory concentration(IC50)was calculated.Flow cytometry was used to analyze the cell cycle,and western blot was used to detect the expression of signal transduction and activator of transcription 3(STAT3)pathway-related proteins in HepG2 cells treated with CSE.A nude mouse model with an orthotopic liver tumor was prepared.The mice were randomly divided into four groups,each containing 12 animals:the model group,the 5-FU group,the CSE10 group[10 mg/(kg·d)]and the CSE50 group[50 mg/(kg·d)].The volume and mass changes in the nude mice with orthotopic transplanted tumors were observed.Western blot method was used to test the protein expression levels of p-STAT3 and p38 mitogen-activated protein kinase(p38MAPK).Tissues from the liver of mice in the model group and the CSE50 group were analyzed by using a protein tyrosine kinase(PTK)chip,and the Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)function enrichment analysis of the differentially expressed proteins was performed.Results This study showed that CSE significantly inhibited the proliferation of HepG2 cells(P<0.05).After 48 h of CSE treatment,the cell cycle of HepG2 cells manifested as S phase and G2/M phase;p-STAT3 protein levels in the CSE groups were significantly lower than that in the control group(P<0.05).Analysis of the tumor inhibition in the mice showed that the tumor masses and volume in CSE groups were lower(P<0.05).The protein levels of p-STAT3 and p38MAPK in CSE50 group and 5-FU group decreased significantly(P<0.05).PTK antibody chip screening results showed that CSE groups had a bidirectional regulation trend,and there were 23 up-regulated PTKs and six down-regulated PTKs.The GO and KEGG analyses showed that CSE exerted its anticancer effects through regulation of biological processes,including mitogen-activated protein kinase(MAPK)cascade,chemotaxis,cell invasion,cell adhesion,angiogenesis and other biological processes,and through signaling pathways,including the MAPK,phosphatidylinositol-3-kinase/serine threonine protein kinase(PI3K/AKT),and RAS signaling pathways.Conclusions CSE can effectively inhibite the proliferation of HepG2 cells and effectively inhibite the growth of liver cancer orthotopic transplantation tumor.Its mechanism may be closely related to the regulation of STAT3,MAPK and PI3K/AKT signaling pathways.

Kinetic study on selective extraction of HCl and H_3PO_4 in a microfluidic device

In the extraction method for preparing KH2PO4, one of the key processes is the selective extraction of HCI over H3PO4. In our work, extraction kinetic studies have been carried out in a microfluidic device with a coaxial microchannel, using the extractant of 33.3% （by volume） trioctylamine （TOA） dissolved in n-octanol, with differ- ent aqueous phases： the HCI solution, the H3P04 solution, and H3PO4 and KCI solutions of different concentra- tions. The changes of the extraction efficiency of HC1 and H3P04 and the selectivity for HC1 along with the residence time were investigated. We found that fast extraction kinetics could be realized in microfluidic devices, and that HC1 could be extracted faster than H3P04 due to smaller mass transfer resistance and much stronger re- action between HCI and TOA. For the extraction of H3PO4 and KC1 solutions, the selectivity for HC1 first increased and then decreased when TOA was in excess of H3PO4 in the initial feeds, and in contrast, always increased when H3PO4 was in excess of TOA in the initial feeds. The diverse changes of selectivity for HCI along with the residence time indicate that a dynamic control of selectivity in microfluidic devices may be important and accessible for im- proving the KH2P04 conversion efficiency in extraction method.

Transcriptomic analysis of Synechocystis sp. PCC6803 under low-temperature stress

In this study, cDNA microarrays were developed from 3569 mRNA reads to analyze the expression profiles of the transcriptomes of Synechocystis sp. PCC6803 under low temperature （LT） stress. Among the genes on the cDNA microarrays, 899 LT-affected genes exhibited a 1.5-fold （or greater） difference in expression compared with the genes from normal unstressed Synechocystis sp. PCC6803. Of the differentially expressed genes, 353 were up-regulated and 246 were down-regulated. The results showed that genes involved in photosynthesis were activated at LT （10℃）, including genes for photosystem I, photosystem II, photosynthetic electron transport, and cytochrome b6/f complex. Moreover, desg, one of four genes that encode the fatty acid desaturases, was also induced by LT. However, the LT conditions to some degree enhanced the transcription of some genes. In addition, LT （10℃） may reduce cellular motility by regulating the transcription of spkA （sll1575）, a serine/threonine protein kinase. The results reported in this study may contribute to a better understanding of the responses of the Synechocystis cell to LT, including pathways involved in photosynthesis and repair.

Electrochemical biosensors and logic devices based on aptamers

Aptamers are molecular recognition elements with high specificity that are selected from deoxyribonucleic acid/ribonucleic acid (DNA/RNA) library. Compared with the traditional protein recognition elements,aptamers have excellent properties such as cost-effective,stable,easy for synthesis and modification. In recent years,electrochemistry plays an important role in biosensor field because of its high sensitivity,high stability, fast response and easy miniaturization. Through the combination of these two technologies and our rational design,we constructed a series of biosensors and biochips that are simple,fast,cheap and miniaturized. Firstly,we designed an adenosine triphosphate (ATP) electrochemical biosensor based on the strand displacement strategy. We can detect as low as 10 nmol/L of ATP both in pure solution and complicated cell lysates. Secondly,we creatively split the aptamers into two fragments and constructed the sandwich assay platform only based on single aptamer sequence. We successfully transferred this design on biochips with multiple micro electrodes (6×6) and accomplished multiplex detection. In the fields of biochips and biocomputers,we designed several DNA logic gates with electric (electrochemical) signal as output which paves a new way for the development of DNA computer.

Understanding the transcriptional control of gene expression using ChIP-chip technology

Gene expression profiling using cDNA or high-density oligonucleotide microarray contributes signifi cantly to our understanding on the transcriptome of a given biological condition. Using this technology, huge number of differentially-expressed genes of interest have been identified in a broad range of circumstances. Making sense biologically on these genes using the recently-improved functional annotation and data integration has leveraged our understanding in diseases and their biological mechanisms. However, understanding the codes encrypt- ed in the cis-aeting regulatory regions and gaining insights into the circuitry of functional regulatory networks on the genomic scale will require additional empirical data sets that are capable of revealing the cohorts or regulons of the transcription and the dynamic progression of molecular events responsible for certain biological function.

Sensory and Organoleptic Characteristic, Zinc and Iron Content of Fortified Chips from Cassava Flour

Iron fortification can cause several biophysicochemical modifications. Those depend on many factors, such as iron fortificant and the food carrier. There were four groups of chips： 1） non-fortified wheat flour chips （K1）; 2） non-fortified cassava flour chips （K2）; 3） fortified cassava flour chips, each with ZnSO4 30 ppm and NaFe EDTA （K3） 30 ppm and 4） fortified cassava flour chips, each with ZnSO4 50 ppm and NaFe EDTA （K4） 50 ppm. The chips were evaluated for sensory characteristic （color, taste, flavor, and texture）, organoleptic characteristics tested by preference test, as well as zinc and iron contents. Zinc and iron contents were analyzed by Atomic Absorption Spectophotometric method. The results showed that both fortificants did not affect the sensory characteristic of cassava flour chips. The preference test showed that color, taste, and flavor of Kl chips as a control, were mostly liked, but there was no significant difference preference of texture. Moreover, preference test using K2 as control showed that color of K3 was mostly liked, but there was no significant difference preference of taste, flavor and texture. Fortification can increase the contents of zinc and iron in cassava flour chips. The panelist can accept the fortified cassava chips as well as wheat flour chip, as a consequence, both can be a potential way to combat the iron deficiency anemia.

Gene Expression Profiles in Porcine Tissues of Liver and Kidney

Microarray technologies are widely used all over the world for the gene expression analysis in various tissues, but still this technology has some limitations. The problem of eliminated reproducibility of the results, obtained in different laboratories using different platforms, is very relevant nowadays. For revelation of problems ofmicroarrays, the comparative analysis of hepatic and renal gene expression profiles （GEP） was carried out by using swine protein annotated oligonucleotide microarrays （SPAM）. Revealed differences in GEP between kidney and liver of pigs were correlated with functional and histological distinctions of these organs. It was shown that sources of errors in the comparative analysis of organ-specific GEP could be connected to the cross hybridization of one probe to transcripts （cDNA of mRNA） of different genes and to individual variability in gene expression between animals, related with the changeability of influences of exo- and endogenous regulation factors.

Covalently derivatized NTA microarrays on porous silicon for multi-mode detection of His-tagged proteins

Porous silicon(PSi)was applied as a supporting substrate for stepwise covalent derivatization of undecylenic acid, N-hydroxysuccinimidyl ester(NHS-ester)and nitrilotriacetic acid(NTA).By taking the advantages of porous silicon as a supporting matrix such as high surface area to volume ratio,infrared transparency,porous semiconductors for laser desorption/ionization mass spectroscopy,and low fluorescence background,a multi-mode detection biochip prototype can be realized. We prepared such a protein microarray by spotting NTA microarray dots on NHS-ester derivatized PSi,converting the rest of chip area into poly(ethylene glycol)background,loading NiII,and finally affinity-binding histidine-tagged(His-tagged)proteins.With the multi-mode analyses of infrared spectroscopy,X-ray photoelectron spectroscopy(XPS),atomic force microscopy(AFM),matrix-assisted laser desorption/ionization mass spectroscopy(MALDI-MS),and fluorescence scanning,two example proteins,His-tagged thioredoxin-urodilatin and His-tagged aprotinin,were well qualified and quantified.

Factors controlling the nitrate in the DT-401 ice core in eastern Antarctica

Nitrate,an oxidized product of NO x preserved in the polar ice cores,has often been used to estimate past changes of the atmospheric nitrogen cycle.A 102.65 m ice core drilled at DT-401(79°01'S,77°00'E) in 1999 provides an opportunity to investigate the possible influencing factors for the nitrate budget in the eastern Antarctica.We studied the relationship between the δ18O(representing the temperature),accumulation rate,volcanic deposition and the astronomical factors(such as the solar activities,supernovae,etc.),and the nitrate variation along the whole duration(2680-year) of the ice core.Prominent impacts of the accumulation rate acting on the nitrate flux rather than the concentration were detected.However,no significant correlation was found between the δ18O and the nitrate deposition characteristics(concentration and the flux variations).Volcanic deposition can significantly affect the deposition of nitrate with a decreasing trend accompanied by the nss-SO42(volcanic signal) peak values.Impacts of the solar activities on the nitrate deposition can be detected at this site,and three prominent periodicities(16.6,24.0 and 102.0 yr) were found for the nitrate concentration variations.Six climatic events(Dalton Minimum,Maunder Minimum,Sporer Minimum,Wolf Minimum,Oort Minimum and Medieval Maximum) during the past 1150 years were observed with lower nitrate values for the foregoing five events and higher value for the last one.